GZipStream size

[qfchen]

Hi,

I'm using GZipStream to comopress a database, before compress the database size is about 300K, but after compress, it become 600K. Why it gets bigger size after compress? below are the code.

Dim ZipFileName As String = Nothing
                ZipFileName = DBbackup.Substring(0, DBbackup.LastIndexOf("\") + 1) & FileName

                Dim srcFile As FileStream = File.OpenRead(ZipFileName)
                Dim desFile As FileStream = File.Create(ZipFileName & ".zip")
                Dim compStream As New GZipStream(desFile, CompressionMode.Compress)
                Dim theByte As Integer = srcFile.ReadByte()
                While theByte <> -1
                    compStream.WriteByte(CType(theByte, Byte))
                    theByte = srcFile.ReadByte()
                End While
                srcFile.Dispose()
                desFile.Dispose()
                My.Computer.FileSystem.DeleteFile(ZipFileName)